Steam superheater



May 27 1924.

J. s. MILNE ET AL STEAM SUPERHEATER Filed Ooi.

20, 1919 3 Sheets-Sheet l oooew eo@ no May 27, 1924.

J. S. MlLNE ET AL STEAM SUPERHEATER Filed Oct. 20'. 1919 3 Sheets-Sheet 2 /A/ VE/v m6 May 27 1924.

J. S. MILNE ET AL.

STEAM SUPERHEATER Filed Oct. 20, 1919 3 Sheets-Sheet' 3 A fr0/mlm,

Patented May 27, 1924.

UNiTD STATES PATENT OFFICE.

J AMES S. MILNE, OF BROOKLYN, NEW YORK, AND ROBERT MCGREGOR. F MONTCLAIR, NEW JERSEY.

STEAM SUPERHEATER.

Application filed October 20, 1919. Serial No. 332,107.

To all whom it may concern.'

Be it known thatI we, JAMES S. MILNE, residing at Brooklyn, in the county of Kings, State of `New York, and ROBERT Motnnoon, residing in the town of Montclair, county of Essex, State of New Jersey, citizens of the United States, have invented a new and useful Steam Superheater, of which the following is a specification.

Our invention consists of a novel' construction of steam superlieater which cali be adapted to existing boilers of every type without necessitatingr any change or disT inaiitling of tlie latter, or employment of special fire tubes, provision being made for readily and expeditiously assembling the superlieating devices with respect to any desii'ed group of fire tubes in an existing boiler.

$0 To the above ends, our invention consistsl of a novel construction of inlet and outlet manifold, adapted to be connected to a series of sectional headers and their adjuncts, which can be cheaply constructed, readily installed in position, with respect to any standard fire tube boilei, and which are con`- venieiitly accessible at all times for the pur# poses of inspection, replacement airs.

It further consists of a novel construction of a superheated steam header or main, an internal preferably cylindrical saturated steam main, an outer superheating tube open at one end and closed at the opposite end, collocated in a novel manner with a satand re'- urated steam circulating tube arranged concentrically within said superheating tube and properly positioned or centered with respect thereto, means being also provided for properly positioning'said outer or superheating tubes with respect to the surrounding ire tube, whereby the relatively coolest steam is conveyed to the hottest part of the superheating tube, thereb-y reducing the temperature of said tube at this point. It further consistsof a novel construction of a saturated steam main wherein the crosssectional area of said main decreases from its inlet end to its terminus. lt `further consists of a novel construction and collocation of one or more valvular manually-operated devices, whereby a predeterininedamount of saturated steam can readily and expeditiously draining the suquirements. v

It further consists of a novel manner of collocating and assembling the superheater elements, whereby the'inner and outer circulating and superheatingI ytubes ycan be readily assembled lor disconnected from the header sections, according to requirements or for the purposes of inspection, replacement or repair.

It further consists of a'novel manner of perheater or its manifolds according to recollocating each superheater element with L respect to its inclo-sing standard tire tube so that the operation of cleaning or the blowing outl ofthe fire tube is not interfered with in any manner. Y-

It further consists of a novel construction of corrugated outer or superheating tube, whereby the effective heating surface or area is increased.

To the above ends, our invention consists of a novel construction of steam superheater, wherein all the tubes are straight and return bends are dispensed with, thereby reducing friction and permitting lany degree of superlieat to be obtained by adding additional rows of tubes, rand wherein a minimum number of joints are employed, thereby reducing theyliability of leakage.

For the purpose of illustrating our invention, we have shown in the accompanying drawings certain forms thereof which are at present preferred, by us,fsince the saine will give in practice satisfactory and reliable results, although it is to Abe' understood that the various instrumentalities of which our invention consists can be variously arranged and organized andthat our invention is not,

limited to the precise arrangement and organization of these yinstrumentalities as herein shown and described.

Figure 1 represents a front elevation of a Scotch marine boiler, showing our novel construction of superheater applied thereto, the boiler casing being removed.

Figure 2 represents on an enlarged scale a vertical section of the upper portion of Figure 1 on line 2-2 of said ligure.

Figure 3 represents on an enlarged scale a transverse section of a header, saturated steam main, a superheatertube and a circulating tube, showing also the relative position of these parts to a standard fire tube.

Figure 4 represents a section on line 4 4 Figure 3.

Figure 5 represents a section on line 5 5 Figure 3.

Figure 6 represents on an enlarged scale,

a section of the right-hand header, its saturated steam main, the outlet manifold, and the controlling valve for admitting saturated steam to the superheater, when desired.

Figure 7 represents on an enlarged scale, in detached position,` a longitudinal section of one of the saturated steam mains seen inY Figure 1, the section being taken on line 7-7 Figure 2.

Figure 8 represents on an enlarged scale, side elevation of our novel corrugated superheater tube, .theV saturated steam main, header and coupling iiange being shown in section. Y

Figure 9 representsa longitudinal seetional view of the parts seen in Figure 8, but showing the circulating tube and outer cor` rugated superheater tube in section.

Figure 10 represents a section on line 10-10 Figure 8. V

Similar numerals of reference indica-te corresponding parts.

Referring to the drawings 1 designates our novel construction of superheater, which is applicable to any type of boiler having standard fire tubes, as a land, marine, stationary or portable boiler, and in the present instance, we have shown a conventional type of Scotch marine boiler, having the main steam outlet 2, controlled by the main stop valve 3, from which leads the main steam pipe 4 to the superheater inlet manifold 5, which may have any number of saturated steam outlets, three being shown in the present instance.

Each of said outlets discharge the saturated steam into the saturated steam main 6, which is preferably constructed as seen in Figure 7 from which lead the circulating tubes 7, which are concentric with or positioned within the outer superheating tubes 8, each circulating tube having its end 9 terminating a short distance from the closed end 10 of its'superheating tube 8, whereby a chamber is formed, so that the relatively cool saturated steam is conveyed to the hottest part of the superheater tube, thereby reducing the temperature at this point.

The inner or circulating tube 7 is always maintained concentric with respect to the outer or superheating tube 8, by means of the radial centering lugs 11, and said outer tube 8 is maintained concentric with respect to the lire tube 12 by the radial lugs 13, as will be best understood from Figures 3 and 4, said fire tubes being secured in their tube sheets 14 and 15, in any suitable or conventional manner, and said tire tubes being of any standard or conventional size, and requiring no change or alteration'when our novel superheater is applied thereto.

The open or left-hand end of the superheater tube 8 seen in Figure 3, is expanded and beaded or otherwise secured at 16 to the flange 17, which is bolted or otherwise secured in any conventional manner to the superheated steam header or main 13, which is preferably tubular and made in sections, as 19, 2O and 21 (as seen in Figure 1) both for convenience in handling and assembling and also to accommodate a plurality of groups of fire tubes. rlhe main 6 is also preferably tubular and is arranged concentrically within the header 18, so that an annular superheated steam chamber 48 is formed.

For convenience Vof installation and simplicity of construction, we preferably make the two outer header sections as 19 and 21 in duplicate, the length of the intermediate section, as 20, varying according to requirements.'

The three right-hand header sections as 21 are connected to the outlet manifold 22, seen at the right of Figure 1, which has the main outlet 23, from which the superheated steam is conveyed to the desired point. rlhe inlet manifold 5 is provided with a drain pipe 24, having a valve 25 therein, and the outlet manifold 22 is proviced with a similar drain pipe 26 having a valve 27 therein, said drains permitting the draining of each of said manifolds according to requirements.

27 designates a Water circulating pipe, having its lower end connected to the bottom of the boiler as at 23, and provided with the valve 29, the upper end of said pipe being connected to the lower portion of the inlet manifold, as at 30, and being provided with the valve 31, as seen at the. left of Figure 1.

The function of the pipe 27 is to provide for a circulation of water between the bottom of the boiler and the inlet manifold 5, and while it is not necessary, yet if desired, this circulation may be accelerated by the employment of a pump or other mechanical device 32, having the suction pipe 33, and the discharge pipe 34 connected to the pipe 27', as indicated at the left of Figure 1. As the pump 32 or its equivalent may be disto the end of one of the saturatedv steam mains 6, preferably the central main 6V as seen in Figure 1, and provided with the elongated valve stein 39 and suitable controlling mechanism 40 and a yoke fastened tothe outside of the outlet lmanifold 22, see Figures 1 and 6, the function of said bypass .valve being to permit the passage of saturated steam directly into said outlet manifold without passing through the superheating tubes 8, whereby in the event of the temperature of the superheated steam becoming excessive, it can be instantly controlled or tempered by mixing saturated steam with said superlieated steam in saidl outlet manifold upon the proper manipu" lation of said valve 38.

It will be understood from Figures 1 and 6, that the upper and lower saturated steam mains 6 are preferably constructed as seen in Figure 7, having their termini or right-hand ends closed, while the central main has its right-hand end open and provided with a valve seat 41, which is controlled by the valve 38, as seen in Figure 6, the valve stem 39 being supported and guided in the spider 42.

It will be obvious that either one of the plurality of mains 6 may have its end open and be provided with the valve 38, but we preferably locate this -valve 'in the central main 6. Each of said mainsV 6 is preferably constructed as tapering from its inlet or'lefthand end to its riglit-hand end, as will be understood from Figures 1 and 7, wherein we have shown said main 6 as composed of a plurality of sections as 43, 44 and 45, whose area in cross-section decreases from left to right, the contiguous )uxtaposed ends of said tubes composing said saturated steam main being suitably secured together at any desired stage in the manufacture or assembling of .the device. Y

As already explained, it will be understood. that the upper and lower mains 6, seen in Figure 3, when three are employed, are con structed substantially as seen in Figure 7, having their right-hand ends closed, while the central main 6 is preferably constructed as seen in Figure 6, and has its right-hand f end open and provided with a valve seat as 41, for the purpose explained.V

46 designates a safetyv valve applied to the upper portion of the outlet manifold 22, for the purpose of preventing excessive pressure in the superheater.

In the construction seen in Figures 8, '9 andv 10, we have shown the employment of -a Aheader 18, saturated ner circulating tube stack.

steam main 6, andinemploy a different form vof superheate'r tube 47 `having itsouter surface corrugated, las vwill be best' understood from Figure 10,

y 7 'and flange 17A of the ,same character as already "described, but

whereby weiare enabled' to gain 40 per cent more lieatingsurface over 'a' plain tube." y lIt will be understood that'in the constructions seen n Figures/2l to5`5, 'we desire to be Ziinderstoodas disclosing the superheater tube 8 as corrugated, asbest seen in Figure l i 10 at 47, but for the sake. of clearness of,V illustration, we have shown'the"corrugated superheater tube particularly on an enlarged scale inv Figures 8 top10. The corrugated tube 47 is provided with the centering `lugsl 13 and is secured to the flange 17 lin Athe y same manner, as already described, y

Thepoperation is as follows and lpasses through the connection 2, valve 3 sa Y' Saturated steaml generated' by theI boilerv main steam pipe 4 into inlet 'manifold5, and

then enters the saturated steam header 64 and flows through circulating tubes 7 into the superheating passes between the outside'of said circu-y Atubes, 8. Theflow is re` lversed in superheatingtubes 8 and the steam lating tube and the inside of' said super` heating tube back into an annular chamber fos 48 between the s'aturated'steam'v header 6 and',y

the main header 18. which has been described with respect to'v one pair of tubes takes place in the plurality of `tubes seen extending acrossthe entire front of boiler in'Figure l1.V

The aboveoperation From the foregoing, it will be seen'that'.

from the time the 'steam ing tube 7 and enters the superheating tube 8, it absorbs a considerable quantity of heat whilel passing between these two tubes, said' tubes 8 beingkcentrally located in the ire tubes 12 of the boiler and preferably running to within about sixinches of'` the coni'i bustion chamber 'end yof said'fire tubes, gases outer periphery of tubes 8 and fthe inner the of combustion travelling betweenv the leaves the circulati ifo periphery o-f tubesm12 on their way to the These gases or products of combustion are obviously vhottest 4at theipoint 10,

Figure 6, which is preferably. located altnthe,`

end of the central saturatedsteam main, 6,

can bel conveniently manipulated vfrom, the exterior of the outlet, manifold to moderate the temperature4 of superheat'jtoany desired f degree;l

der 18 andsaturated y `where the relatively cool saturated steam first comes in contactY with thesupe'rheat- In otherewords,`1should thegdegreejef z' perheatflbe higher than; desired,. the*valve*V 38 can be opened;slightly:thereby permitting the saturatedlsteam :toy flew ,directly into the outletl manifold. 22,1`inixing. therein with f the superbeatedl steam .andgieducing Vthe temperature, thereofgtofariy ,1. .degree desired. i n l locity- .of thesame. and increasing the time whichit takesfor the steam to pass through the superheater, this .constructionv giving the steam" ampletiineto absorb considerably more heat` units than if i its velocity Ahad Y not A been reduced.: l v

Th'valve 46. ispnefgrablya. Smau Spring loaded safety valve .which ifs iittedfat sonne..`

convenient. point...on the. outletfnianifold 22,

preferably at lupper. portionlthereof, f to` relieverexcessfive .press s: ,'.withi-n the; super; heater, which*l might, caused by lclosing the throttle valveoi'i4 thein giiiev and at .the

same time .closing the main stfipQvaIVeon.r

l safety valvew By v'providing the; mani?` Y .vieniently installed, since after manifolds 5 the boiler,"v iii-.which event, the wouldv function,

folds 5 land 2 2wit-h drains leading `to4 some convenientpoint, thesel drainsfcan' be used; by the operating. engineer `to carry away any. accumulation of water `which may take place in theV superheater.,` f

Byfopening the proper .valves inthe pipes. and 35, the entire. superheater .unit canVV be tlooded with water 1lup.to'.the.boilerwateri level, .which .is desirableffwheii .itis desired. Superheater unit, A.while ,"fsteain is beingl Q raisedfliin .l the L.

to circulate lfwaten."throughti boiler,j .the 'auxiliary f pump,f32` nected` to the;.intake.lf.line` ,.27.v l y adaptedto.augment.k the circulation, if `desired, .it being apparent that .the presence of Water in the. superheater. .when steamis being; raised. in, the boilers, Vprecludes.the possibility .of burning ,the superheatertube end l0, yFigure 3, and it beingl further ap-- parent that this feature Y`of circulating, the water .in v the superlieater permits.V the rai'sing oflvsteainnina shortertime thanheretofore, .which is especially,aplfiarenft` when a pump, vas i32fis used. @As Asoon as steam forms in the boiler', valves` asi. and 31 are closed by theoperator andfthedrain valves.

25 and 27 are opened,- .therebyfpermitting the.

superheater to be emptied,whereupon itlcanf.

perform.its function as a superheater.

Our entire apparatus. isadaptable-.to boilers already in commissionwithout,any mal terial change in their construction, since we do not have to alteror increasethe .sizeof the fire tubes, anddo. not. occupy vsufficient space in the .uptakes to .afi'ectthe flow or exit'of the gases of combustion." vTheV in;v

stall'ation. .start-ing atfthe .Inain. fstop valve 5 3 consistsv merely of Va pipe line' Vleading to l fold 22. As will be noted from Figure 2, the head- Vheader 18.

4.other devices, .l the like.

theinlet manifold 5, to] which the transverse headers. arev bolted, the opposite ends of the right-hand transverse headers being ,opposite end of each main 6 being blanked ofi' in any suitable manner, excepting where fitted with the valvev 38, see Fig. 6.

7e desire to callspecial attention to the .gradual reduction in sectional area as from left to right of the saturated which reduction increases the effective area between the outside of the main 6 and the inside of the header 18, the area being small-- estat the extreme left and gradually increasing in size until its maximum at the extreme `rig'ht,vwhere the greatest amount of steam .must pass in order to enter the outlet maniers are staggered in such a manner as to permit accessibility to the flange connections 17, which are readily removable at all times.

Our header can be expeditiously and conand 22 are bolted in position, a superheating tube 8 made up'in flange 17 is entered into each lire tube 12, which we may desire to utilize.` y The circulating tube 7 is then entered into the superheating tube 8. The lefthand section of the top header is then bolted in position,eand.the first section of the sat-- urated steam main 6 is secured in place. The

.central section of the top header is then bolted in placeand the central section of the .superheated steam main 18 is secured into lt'heviirst section. l The third section of the fsaturatedsteam main 6 is then secured into .the central section, and the right-hand .sec-

tion of the header 18 is then bolted in place. v"After this is completed, the circulating tubes 7 are enteredand screwed into the saturated V, steaminain v6, afterwhich the superheating tube 8 is slipped out and made fast to the `This concludes the top row of the top header and the assembling of the other headers follows in similar order.

It will be apparent that the broad principle of our invention can be employed in such as feed water heaters and l, v,It willnow be apparent that we have devised a ynovel and useful steam superheater` which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and While we have, in the present instance,shown land described preferred embodiments thereof which will give in practice satisfactory and reliable results, it is to be understood that the same is susceptible of modification vin various particulars without departing steam pipe G,`

lll() from the spirit or scope or the inventionkor sacrificing any of its advantages.

Having thus described our invention, What We claim as new and desire to secure by' Letters Patent, is

l. In a superheater, a header, a saturated steam main located Within said header, and tapering from its open inlet end to its terminus, steam superheating devices common to said header and saturated steam main, and a valve for controlling the smaller end o said saturated steam main Jfor admitting saturated steam to the exit portion of the superheater When desired.

2. In a superheater, a header, a saturated steam main located Within said header and of decreasing cross sectional area from its inlet end to its terminus, outer superheating tubes having one of their ends closed and their opposite ends secured to said header, and inner open-ended circulating tubes having one of their ends secured to said main and their opposite ends discharging against the closed ends of said superheater tubes, in combination With a valve for controlling the smaller terminal end of said saturated steam main to the exit portion of said superheater. Y

3. In a steam superheater, an inlet manifold, an outlet manifold, headers common to said manifolds, a saturated steam main located within said headers and decreasing in cross-sectional area from its inlet end to its terminus, superheater tubes having one o their ends closed and their other ends secured to said header, and open-ended circulating tubes contained Within said superheater tubes and having one of their ends secured in said saturated steam main and their oppoiste ends discharging against the closed endof said superheater tubes, in combination With a valve for controlling the smaller terminal end of said saturated steam main to the exit portion of said superheater.

4. In a steam superheater, an inlet manifold, an outlet manifold, a series of headers common to said manifolds, saturated steam mains located in said headers and having their cross-sectional area gradually reduced from theirV inlet ends .to their termini, all of said mains having closed ends except one, which is providedy With ya valve seat, steam superheating devices common to said headers and mains, and a valve cooperating with said valve seat for effecting the commingling of saturated steam with the superheated steam in said outlet manifold.`

J AMES S. MILNE. ROBERT MGGREGOR. t

Witnesses: K

R. J. VANDERWENDE, GEO. P. HAYNEs. 

